There's a museum in Oslo (can't remember which one) that has a book like this. The book is really big, like an old school story book, and it's fixed into the table, there's maybe 10 pages. They have a projector in the ceiling above the book projecting images so they fit exactly onto the pages in the book. Each page has an invisible rfid-chip embedded in the paper so when you turn the book some sensor knows which page you have open and the projector changes page accordingly. (it also displays video and has touch-interface but that's irrelevant for this discussion). It feels magic to flip through it even though the implementation is quite trivial once you decompose it. Too bad it can't be done without having it in a fixed location.

When you are a group of people it is much easier to flip through and keeping a mental map over physical pages instead of fighting over who gets to control the scrollbar on a computer. But admittedly, it is also a bit gimmicky.

Differing page counts and all that aside, a UI feature I like is being able to locate content based on relative location, which is especially handy when I can recall the general concept but not specific search terms.